Card tray follower

ABSTRACT

An improved follower for use in association with a card file or like tray of the type having a follower guide track and follower positioning teeth extending lengthwise of its bottom wall. The follower features a latching mechanism including a vertically reciprocating latch flange, which is normally spring biased downwardly for locking engagement with the positioning teeth. The latch flange carries adjacent its lower end a rearwardly directed flange defining a downwardly facing convex cam surface dimensioned to be received within a space between adjacent teeth and a pair of coplanar supporting surfaces. The supporting surfaces forwardly and rearwardly bound the cam surface to normal reside in engagement with upwardly facing edges of the teeth, whereby to limit the extent to which the cam surface projects into the space between the teeth.

United States Patent Little 5] Apr. 24, 1973 CARD TRAY FOLLOWER Primary Examiner-Samuel B. Rothberg [75] Inventor: Carl H. Little, Jamestown, NY. Assistant Exammer steven Pollard At!0rney-John B. Bean et al. [73] Assignee: Weber-Knapp Company,

Jamestown, N.Y. [57] ABSTRACT [22] Filed: Dec. 29, 1971 An improved follower for use in association with a 2 A L N 213 card file or like tray of the type having a follower l PP 0 guide track and follower positioning teeth extending lengthwise of its bottom wall. The follower features a 2 latching mechanism including a vertically reciprocat- [51] Int. Cl. ..B65d 1/24 ing latch flange, which is normally spring biased [58] Field of Search ..220/22.3, 22.2, 22.4, downwardly for locking engagement with the position- 0/ 74/527 ing teeth. The latch flange carries adjacent its lower end a rearwardly directed flange defining a [56] References C l downwardly facing convex cam surface dimensioned to be received within a space between adjacent teeth UNITED STATES PATENTS and a pair of coplanar supporting surfaces. The sup- 3,547,3ll 12/1970 VanBuren 220/223 porting surfaces forwardly and rearwardly bound the 3,370,591 2/1968 Coe ..220/22.5 cam surface to normal reside in engagement with up- I 3,204,640 9/1965 wardly facing edges of the teeth, whereby to limit the 2,860,643 11/1958 Senechal ..220/22.3

extent to which the cam surface projects into the space between the teeth.

5 Claims, 3 Drawing Figures Patented April '24, 1973 26 5a 50 INVENTOR. b! I Q, CARL H. LITTLE k W 42 W BY 28 "a v j \\\\\\\\\\\\\w 6 :I3IIYII7IVI7'IE'QI-IZ5ZAFI'TII7III-II7'I7 Qua/M 6 ATTORNEYS CARD TRAY FOLLOWER BACKGROUND OF THE INVENTION Followers are conventionally provided as adjustable backups for a stack of cards filed in a tray, such as may be employed in a library. Usually these followers include an upstanding plate arranged to engage the rear of the stack of cards; a guide flange arranged to slide within a guide track extending lengthwise of the bottom of the tray; and a latch mechanism, which is movably carried adjacent the rear of the upstanding plate for locking engagement with positioning teeth spaced lengthwise of the bottom of the tray. As by way of further illustration, reference is made to US. Pat. No. 2,236,807. a

A decided drawback of the above construction is that should a tray filled with cards be dropped, the weight of the stack of cards bearing against the up standing plate will ofttimes cause the latching mechanism to be bent or, if the teeth are formed of a plastic material, it will cause one or more of the teeth to be sheared off.

SUMMARY OF THE INVENTION The present invention relates to followers for card or like storage trays and more particularly to an improved follower construction for overcoming the disadvantages of the prior art.

The follower of the present invention is formed with DETAILED DESCRIPTION Reference is now made particularly to FIG. 1, wherein the follower of the present invention is generally designated as 10 and is shown in association with an elongated card tray 12 of the type adapted to store a stack of cards or the like, not shown. Tray 12 may be of any suitable construction, but is shown for the purposes of illustration as being of integral, molded plastic construction having a front wall 14, a rear wall 16, side walls 18 and a bottom wall 20. If desired, a decorative front panel 22 may be affixed to front wall 14 as by fasteners 24 and a follower rod 26 may be removably inserted rearwardly through from 22, front wall 14 and follower 10 for the purpose of retaining a stack of cards intermediate the follower and the front wall.

In FIGS. 1-3, tray bottom wall 20 is shown as being formed with a lengthwise extending, upwardly opening guide slot 28, which is bounded by a pair of facing lips or flanges 30; lips 30 being cut away or removed adjacent the front end of the guide slot, as at 32, to permit insertion of follower 10 thereinto. A plurality of essenwithin spaces between adjacent teeth and planar supporting surfaces,' which forwardly and rearwardly bound the cam surface. These supporting surfaces normally reside in engagement with the upwardly facing edge surfaces of the teeth and serve to limit the extent to which the cam surface projects into the space between the teeth. Thus, should an impact force be applied to the upstanding plate, the cam surface is freed to move out of and into engagementwith successive teeth, thereby to free the follower for movement rearwardly within the card tray.

DRAWINGS The nature and mode of the present operation will now be more fully described in the following detailed description taken with the accompanying drawings wherein:

FIG. I is a perspective view of a card tray showing the follower of the' present invention installed therewithin;

FIG. 2 is a sectional view of the tray of FIG. 1 showing the follower in rear elevation; and

FIG. 3 is a sectional view taken generally along line 3-3 in FIG. 2.

tially equally spaced apart teeth 34 are arranged co-extensive with lips 30 and have their upwardly facing edge surfaces disposed essentially flush with the bottom surface 36 of slot 28. As desired, teeth 34 may be of square cross-sectional configuration, as shown in FIG. 3, or be tapered in a direction towards their upper edge surfaces.

Follower 10 generally includes a card stack engaging metal plate 40, which is supported to extend transversely of tray 12 for movement between end walls 14 and 16 by a generally L-shaped metal mounting flange 42 receivable within guide slot 28; and a latching mechanism 44 including a generally U-shaped metal latch flange 46 and a coil spring 48. For tray constructions utilizing a follower rod, plate 40, flange 42 and flange 46 are formed with aligned apertures 50, which are dimensioned to freely receive the follower rod therewithin.

By referring to FIGS. 2 and 3, it will be understood that flange 42 is formed with a generally rectangular foot portion 52, which is provided with a slight upward bow such that its marginal edge portions engage surface 36 immediately beneath lips 30, whereas its mid portion is disposed in a slightly spaced relationship relative to the upwardly facing edge surfaces of teeth 34. Flange 42 is rigidly affixed to the rear surface of plate 40 by deeply peening the front or shank ends of a pair of headed fasteners or rivets 54, which fasteners extend rearwardly through a pair of plastic anti-friction washers 56 and vertically extending slots 58 formed in latch flange 46. By this means, flange 42 and plate 40 are rigidly joined together, whereas latch flange 46 is supported for vertical reciprocated movement relative thereto.

Latch flange 46 is rearwardly bent adjacent its upper end to define a finger lift portion 60 and adjacent its lower end to define a rearwardly directed flange portion 62. As best shown in FIG. 3, flange portion 62 is shaped to define a downwardly facing convex cam surface 64, which is dimensioned to be received within the spaces between adjacent teeth 34, and planer supporting surfaces 66 and 68, which forwardly and rearwardly bound cam surface 64. It will be understood that coil spring 48 normally serves to resiliently bias surfaces 66 and 68 downwardly to lie in engagement with the upwardly facing edge surfaces of teeth 34, thereby to limit the extent to which cam surface 64 projects downwardly into the space between teeth 34. Preferably, the depth of each of the spaces is in excess of the height of the cam surface by at least an amount sufficient to accommodate for the total amount of teeth wear expected during the life of the file tray.

When it is desired to adjust the position of follower l lengthwise of slot 28, it is merely necessary for an operator to lift finger tab portion 60 against the bias of spring 48 by an amount sufficient to lift cam surface 64 into a position above the upwardly facing edges of teeth 34. Preferably, the width of cam surface 64 in the direction of follower movement, that is the distance between surfaces 66 and 68 is only slightly less than the spacing between adjacent teeth in order to minimize movements of the follower when in a latched condition.

A particularly important feature of the above described construction is that when a rearwardly directed impact force is applied to plate 40, such as for instance when a tray full of cards is dropped on its rear end wall 16, cam surface 60 is free to move or cam" itself out of and into engagement with successive teeth 34 against the bias of spring 48 in order to free the follower for movement rearwardly within the card tray, whereby to prevent damage to either flange portion 62 or teeth 34. In effect, successive tensionings of spring 48, as latch flange 46 is vertically reciprocated, tends to absorb the impact load and to eventually arrest rearward movement of the follower.

An additional advantage of the present invention is that the effective height of teeth 34 relative to cam surface 64 is maintained constant regardless of anticipated teeth wear, due to engagement of surfaces 66 and 68 with the wearing surfaces of such teeth. ln view of the diminutive changes in spring force occasioned by the progressive downward movement of the latch flange as the teeth wear, the constant height relationship of the teeth and the cam surface insures essentially uniform latch release operating characteristics over the anticipated life of the card tray.

I claim:

1. A card or the like file tray, wherein a card follower is mounted by a guide device within the tray for sliding movement lengthwise thereof and releasably locked in a desired position by a follower mounted latching mechanism arranged for releasable engagement with essentially equally spaced teeth of a rack extending essentially co-extensive with said guide device, the improvement for permitting movement of said follower rearwardly along said guide device upon application to the follower of the rearwardly directed impact force without damage to the latching mechanism or teeth of the rack, wherein:

said latching mechanism includes a vertically movable lower end portion disposed rearwardly of said follower and biased downwardly for releasable engagement with said teeth, said lower end portion defining a downwardly facing convex cam surface dimensioned to be received within the spaces between adjacent rack teeth and at least one supporting surface arranged adjacent said cam surface, said supporting surface limiting the extent to which said cam surface projects into said spaces. 2. The improvement according to claim 1, wherein said portion defines a pair of essentially co-planar supporting surfaces, said supporting surfaces forwardly and rearwardly bounding said cam surface relative to the direction of sliding movement of said follower within said tray and being normally engageable with upwardly facing edge surfaces of said rack teeth to limit the extent to which said cam surface projects into said spaces as aforesaid.

3. The improvement according to claim 1, wherein said cam surface has a dimension measured lengthwise of said rack essentially corresponding to the spacing between said adjacent rack teeth, whereby to prevent movements of said follower lengthwise of said rack when said cam surface is disposed in a space between adjacent teeth.

4. A follower for use in combinations with a card file or like tray, wherein said tray includes a guide track extending lengthwise of a bottom wall of said tray and a rack arranged to extend essentially co-extensive with said guide track, said rack defining a plurality of essentially equally spaced apart teeth, said follower comprising in combination:

a plate;

a mounting flange fixed to said plate, said mounting flange having a guide portion extending forwardly beneath of said plate for engagement with said guide track whereby to support said plate above said guide track to extend transversely of said guide track for sliding movements lengthwise of said tray; and

a latching mechanism including a latch flange supported on said plate and mounting flange for vertical reciprocating movements relative to said rack and spring means for normally biasing a lower end portion of said latch flange downwardly into engagement with said rack, said lower end portion carrying a downwardly facing convex cam surface dimensioned to be received within spaces between adjacent teeth and a supporting surface arranged adjacent said cam surface, said supporting surface limiting the extent to which said cam surface projects into said spaces by engagement with the upwardly facing edge surface of at least one of said teeth.

5. A tray according to claim 4, wherein said lower end portion defines a pair of essentially co-planar supporting surfaces, said supporting surfaces forwardly and rearwardly bounding said cam surface relative to the direction of sliding movement of said follower within said tray and being normally engageable with upwardly facing edge surfaces of said rack teeth to limit the extent to which said cam surface projects into said spaces as aforesaid. 

1. A card or the like file tray, wherein a card follower is mounted by a guide device within the tray for sliding movement lengthwise thereof and releasably locked in a desired position by a follower mounted latching mechanism arranged for releasable engagement with essentially equally spaced teeth of a rack extending essentially co-extensive with said guide device, the improvement for permitting movement of said follower rearwardly along said guide device upon application to the follower of the rearwardly directed impact force without damage to the latching mechanism or teeth of the rack, wherein: said latching mechanism includes a vertically movable lower end portion disposed rearwardly of said follower and biased downwardly for releasable engagement with said teeth, said lower end portion defining a downwardly facing convex cam surface dimensioned to be received within the spaces between adjacent rack teeth and at least one supporting surface arranged adjacent said cam surface, said supporting surface limiting the extent to which said cam surface projects into said spaces.
 2. The improvement according to claim 1, wherein said portion defines a pair of essentially co-planar supporting surfaces, said supporting surfaces forwardly and rearwardly bounding said cam surface relative to the direction of sliding movement of said follower within said tray and being normally engageable with upwardly facing edge surfaces of said rack teeth to limit the extent to which said cam surface projects into said spaces as aforesaid.
 3. The improvement according to claim 1, wherein said cam surface has a dimension measured lengthwise of said rack essentially corresponding to the spacing between said adjacent rack teeth, whereby to prevent movements of said follower lengthwise of said rack when said cam surface is disposed in a space between adjacent teeth.
 4. A follower for use in combinations with a card file or like tray, wherein said tray includes a guide track extending lengthwise of a bottom wall of said tray and a rack arranged to extend essentially co-extensive with said guide track, said rack defining a plurality of essentially equally spaced apart teeth, said follower comprising in combination: a plate; a mounting flange fIxed to said plate, said mounting flange having a guide portion extending forwardly beneath of said plate for engagement with said guide track whereby to support said plate above said guide track to extend transversely of said guide track for sliding movements lengthwise of said tray; and a latching mechanism including a latch flange supported on said plate and mounting flange for vertical reciprocating movements relative to said rack and spring means for normally biasing a lower end portion of said latch flange downwardly into engagement with said rack, said lower end portion carrying a downwardly facing convex cam surface dimensioned to be received within spaces between adjacent teeth and a supporting surface arranged adjacent said cam surface, said supporting surface limiting the extent to which said cam surface projects into said spaces by engagement with the upwardly facing edge surface of at least one of said teeth.
 5. A tray according to claim 4, wherein said lower end portion defines a pair of essentially co-planar supporting surfaces, said supporting surfaces forwardly and rearwardly bounding said cam surface relative to the direction of sliding movement of said follower within said tray and being normally engageable with upwardly facing edge surfaces of said rack teeth to limit the extent to which said cam surface projects into said spaces as aforesaid. 